HUGHES: PARASITES OF PACIFIC SAURY 



were Pennella sp. and C. macarovi since insuf- 

 ficient data excluded use of the acanthocepha- 

 lan. 



As previously shown, infections by Pcunvlla 

 sp. increased with increasing host age, and C. 

 macarovi infections were found to be indepen- 

 dent of host age or length. Accordingly, chi- 

 square tests of Pennella sp. infections were 

 conducted for spring-born versus autumn-born 

 fish by individual age groups for each area 

 during 1970. C. macarovi infections were 

 compared after combining all host age groups 

 within each area for 1970 and 1971. 



Results of chi-square tests are summarized 

 in Table 5. The only significant difference in 

 numbers of saury infected by Pennella sp. 



occurred between spring- and autumn-born 

 Il-year-olds captured off Oregon in 1970. No 

 significant differences between numbers of 

 spring- and autumn-born saury infected by 

 C. macarovi existed in either area during 1970 

 and 1971. 



CONCLUSIONS AND SUMMARY 



The eastern Pacific saury was found to be 

 infected with two species of copepods and one 

 acanthocephalan, in addition to being scarred 

 from previous copepod infections. Mean inci- 

 dence of Pennella sp. infections was 18.4% off the 

 Oregon coast and 14.5% off the Washington 

 coast in 1970, but this parasite was rarely found 



Table 5. — Numbers and percentage incidence of copepods {Pennella sp. and Culi:^iis macarovi) in two possible sub- 

 populations of eastern Pacific saury. Chi-square values are presented testing the null hypothesis that no significant difference 

 in numbers of infections exists (0.05 level) between the hypothesized spring- and autumn-born fish. Fish ages are in 

 parentheses. 



Year and 



ceo 



Pacific saury 



examined for 



Pennella sp. 



Number of saury 



Noninfected 



I nfected 



Total 



I ncidence 



of 

 infection 



Null 

 hypothesis 



Accept 



Reject 



1970: 



Washington 



Oregon 



Spring born (II) 

 Autumn born (II) 

 Spring born (III) 

 Autumn born (III) 



Spring born (II) 

 Autumn born (II) 



Spring born (III) 

 Autumn born (11 h 



221 

 51 



103 

 63 



154 

 86 

 23 

 15 



47 



7 

 45 

 33 

 64 

 16 

 13 

 19 



268 



58 

 148 



96 

 218 

 102 



36 



34 



17.5 

 12.7 

 30.4 

 34.4 

 29.4 

 15.7 

 36.1 

 55.8 



1.03 



0.42 



6.93 



2.70 



0.01 



Year and 

 area 



Pacific saury 



examined for 



Caliinis macarovi 



Number of saury 



Noninfected 



Infected 



Total 



Incidence 



of 

 infection 



(%) 



\2 



Null 

 hypothesis 



Accept 



Reject 



1970: 

 Washington 



Oregon 



1971: 



Washington 



Oregon 



Spring born 

 Autumn born 



Spring born 

 Autumn born 



Spring born 

 Autumn born 



Spring born 

 Autumn born 



329 

 126 

 503 

 118 



368 

 96 



1,211 

 150 



25.7 

 22.7 

 12.4 

 15.7 



8.0 

 13.5 

 6.4 

 9.6 



0.58 



1.11 



3.16 



2.42 



951 



